The present invention is generally directed to polyester resin compositions and process thereof, and more specifically, a branched polyester, especially useful as a toner binder, and which resulting toner can be selected for imaging and printing processes. In embodiments, the polyester of the present invention is comprised of a branched polyester resin of the Formula ##STR3##
wherein n and m represent randomly repeating segments, for example the segments in ( ) are not in a particular sequence or pattern, and more specifically, represent repeating segments of the polymer backbone and randomly distributed such that the repetitive sequence of the segments n and m do not follow any algorithm, and the number of n and m segments in the polymer backbone are each, for example, of from about 10 to about 10,000 (from about to about as used throughout includes, for example, all numbers in between, such as 11, 12, 25, 100, 1,000, 5,000, 7,000), X is an aliphatic group of for example, from about 2 to about 20 carbon atoms, an olefinic group of, for example, a vinylidene group, or an aromatic group of, for example, from about 6 to about 18 carbon atoms, Y is selected from the alkoxylated bisphenol A units illustrated as groups or radicals I, II and/or III, and wherein I, II and/or III comprise, for example, a mixture of I from about 60 to 90 percent of the mixture, II from about 1 to 30 percent of the mixture, and III from about 0 to about 10 percent of the mixture; Z is selected from the branching units (p) illustrated as radicals or groups IV and V, and wherein R and R.sub.1 are a hydrogen atom or aliphatic hydrocarbon, such as alkyl with from about 1 to about 20 carbon atoms, and (a) is preferably, for example, 0 or 1. ##STR4##
In a specific embodiment of the present invention, the branched polyester resin is derived from the polycondensation reaction of an equivalent of a diacid monomer, such as for example, fumaric acid or terephthalic acid, and an equivalent mixture of bis-alkoxylated bisphenol A with a hydroxyl number of from about 2 to about 4 illustrated herein by Formulas IX, X, XI, XII and XIII.
In another embodiment of the present invention, there is disclosed a process for the preparation of a mixture of bis-alkoxylated bisphenol A with a hydroxyl number of from about 2 to about 4 as illustrated by Formulas IX, X, XI, XII and XIII, involving the alkoxylation of bisphenol A with a cyclic alkylene carbonate in the presence of a catalyst, such as an alkali carbonate, and wherein the cyclic alkylene carbonate is, for example, an ethylene carbonate, propylene carbonate, butylene carbonate as illustrated by Formula VI, and a hydroxyl containing cyclic carbonate, such as glycerine carbonate and/or trimethylolpropane carbone, illustrated as VII and VIII, respectively. ##STR5##
wherein R.sub.2 is a hydrogen, or an alkyl group.